In conventional thinning of young trees by means of machines travelling on strip roads, such roads are made in the forest stands and in order to ensure maximum yield from the remaining, thinned forest, the strip roads should be spaced as far as possible from each other. In practice, however, these strip roads, primarily because of the limited range of operation of the cranes carrying the felling or processing equipment, cannot be located at a distance from each other of more than about 30 m and then are in the form of substantially parallel, straight roads. In practice, available machines require a width of about 4 m, which means that the strip roads must have a minimum width of 4 m. This combination of relatively small spacings between the strip roads and their considerable width results in that the finally thinned stands will contain far too large areas without any trees, this notably reducing the total productivity of the stands. A highly contributory reason for poor total productivity also is that the strip roads--in order not to leave any unthinned spots in the forest stands--are made substantially rectilinear. In this way, the operator is often forced to fell first-quality, vigorous trees situated in the linear extent of the road while less vigorous trees are left in the immediate vicinity of the road.